The proper selection of offshore wind turbines is crucial for the long-term efficient operation of offshore wind farms. Aiming at the problems of uncertainty and subjective preference of decision-makers in the decision-making process of wind turbine selection, this paper proposes an improved Multi-criteria Decision Making (MCDM) framework and method: in the weight solving algorithm, group decision and intuitionistic fuzzy numbers are combined with analytic hierarchy process, and the group intuitionistic fuzzy analytic hierarchy process (GIAHP) is proposed to calculate the index weight; in the alternative ranking algorithm, the cosine distance is introduced into the Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS), and the multi-distance TOPSIS is proposed to determine the alternative ordering. Finally, taking the selection of wind turbines in offshore wind farms in Shandong Province as an example, the robustness of the framework and method is verified by sensitivity analysis. This framework and method can provide a theoretical basis for the selection of wind turbines in China"s offshore wind farms and ensure the long-term stable operation of offshore wind farms.